U.S. Philips Corporation

Phenom-world Holding B.v.

Other

Fei Comapny

Karel D Van Der Mast

Sander Richard Marie Stoks

Adrianus Franciscus Johannes Hammen

Pieter Kruit

Gerardus G Van Gorkom

Alexander Henstra

Arthur M Hoeberechts

Wilhelmus Henrica Cornelis Theuws

Harald Rose

Harm Tolner

Marcellinus P Krijn

Ulrich Gross

Jan B Le Poole

Johan G Bakker

Alan F De Jong

Kars Z Troost

Ton Antonius Cornelis Henricus Kluijtmans

Ralf Degenhardt

Jan Bart LePoole

Gerhardus Bernardus Stamsnijder

Christiaan J Rakels

Paul Cornelis Maria Van Den Bos

A scanning electron microscope. The scanning electron microscope may include a sliding vacuum seal between the electron optical imaging system and the sample carrier with a first plate having a first aperture associated with the electron optical imaging system and resting against a second plate having a second aperture associated with the sample carrier. The first plate and/or the second plate includes a groove circumscribing the first and/or second aperture. The scanning electron microscope may include a detector movable relative to the electron beam. The scanning electron microscope may include a motion control unit for moving a sample carrier along a collision free path.

Scanning electron microscope

A scanning electron microscope () including a sliding vacuum seal () between an electron optical imaging system () and a sample carrier () with a first plate () having a first aperture () associated with the electron optical imaging system and resting against a second plate () having a second aperture () associated with the sample carrier. The first plate and/or the second plate includes a groove () circumscribing the first and/or second aperture. The scanning electron microscope may include a detector () movable relative to the electron beam. The scanning electron microscope may include a motion control unit for moving a sample carrier along a collision free path.

Sample stage, e.g. for use in a scanning electron microscope. The sample stage includes a base, a sample carrier, and an actuator assembly arranged for moving the sample carrier in at least one direction substantially parallel to the base. The actuator assembly is arranged so as not to contribute to the mechanical stiffness of the sample stage from the sample carrier to the base.

Sample stage

Particle-optical rotationally symmetrical lenses inevitably have chromatic aberration. This lens fault determines the limit of the resolution of known particle-optical apparatus at a comparatively low acceleration voltage (0.5 kV to 5 kV) of the particle beam. This lens fault cannot be eliminated by compensation by means of rotationally symmetrical fields. In order to enhance the resolution of the particle-optical apparatus nevertheless, it has already been proposed to mitigate said lens fault by means of a Wien type corrector. Such a known configuration is provided with a number of electrical and magnetic multipoles. In order to achieve easier adjustment of the various multipole fields, the pole faces (30-i) governing the multipole fields according to the invention have a specific length L=(2.pi..sup.2 n.sup.2)/(K.sub.obj.sup.2 C.sub.c,obj), in which K.sub.obj is the strength of the focusing lens to be corrected and C.sub.c,obj is the coefficient of chromatic aberration of this lens.

Correction device for correcting chromatic aberration in

The focusing device 8 for the primary beam in a scanning electron microscope (SEM) consists in known manner of a combination of a magnetic gap lens 34 and a monopole lens 38. The secondary electrons released from the specimen are detected in accordance with the invention by a detector whose deflection unit 52, or the actual detector 64, 66, is arranged in a field-free space between the gap lens and the monopole lens. This space is rendered field-free by a screening plate 44 arranged underneath the gap lens. In order to achieve a high detector efficiency and a large field of vision, the pole tip of the focusing device 8 is provided with an attraction electrode 42 whose potential is higher than that of the specimen.

Particle-optical apparatus comprising a detector for secondary electrons

An electron beam apparatus is provided with an energy selective device which enables spectrometric measurements together with imaging. The energy selective device has its main electron beam trajectory in a plane outside the optical axis of the electron beam apparatus, thereby substantially reducing the overall length of the apparatus. Preferably the energy selective device has double symmetry such that the energy dispersion has a maximum value in a central plane of symmetry where a selective slit can be introduced. Full symmetry facilitates full compensation of optical aberrations in the device. Adding quadruples in a second plane of symmetry enables imaging of spectra at a location outside the device.

Electron beam apparatus

A method and apparatus for selecting the spatial energy spread of an electron beam for producing an image of an object, as in an electron microscope. An energy-dispersive member is arranged in the vicinity of the electron beam source to widen the electron beam in a dispersion direction. Selection of an energy dispersion within the beam is achieved by selecting a number of pixels having such a local energy dispersion in the image plane of the object.

Method of selecting a spatial energy spread within an electron beam, and

In an electron microscope correction of spherical and chromatic aberration can be achieved in a number of freely adjustable directions by using a multipole correction element whereby a magnetic or electrostatic octupole field, rotatable about the optical axis, or a combined rotatable magnetic and electrostatic quadrupole field is generated. A corrected overall image can be obtained by combination of images successively corrected in different directions. In the case of holographic images, correction in the direction perpendicular to the line direction in the hologram enhances the accuracy of phase determination. A correction element of this kind, having comparatively small dimensions of from 1 to 2 cm, can be simply mounted, notably in a transmission electron microscope, in a space provided for the stigmator.

Charged particle beam device

A charged-particle beam apparatus comprises a beam splitting/alignment system whereby individual beams or groups of individual beams can be independently aligned so that they can be brought out of focus in a focal plane of the individual beams, so that a beam limiting diaphragm arranged at that area is irradiated more uniformly with a smaller beam loss.

Charged-particle beam apparatus

A Variable Axis Lens system comprises at least two lenses which are arranged to be radially offset with respect to an optical axis of the apparatus. Because the lenses do not contain iron, the occurrence of disturbing eddy currents can be prevented. The lenses for axis displacement are preferably constructed as single ring conductors, a number of which can be readily arranged in one plane in a partly overlapping fashion. Such a system can also be arranged behind the object. For the lenses for axis displacement use is preferably made of a ceramic superconducting material having a comparatively high temperature coefficient and a comparatively high specific heat in the superconducting phase, so that they can be simply cooled from the outside.

Charged particle beam apparatus

An electron image projector for transferring mask patterns onto a semiconductor wafer comprises a patterned photo-emissive cathode mask (1) and a target (3) such as a semiconductor wafer (11) coated with an electron sensitive resist (10). Accelerated by a uniform electric field E and focussed by a uniform magnetic field H a patterned electron beam is projected from the cathode onto the target with unity magnification. The electric field E is at least mainly established between the cathode and the target A foil is provided for protecting the photocathode against poisoning by gas liberated from the target upon electron beam bombardement. To avoid adversely influencing the imaging electron beams the foil may be constituted as a metal foil with a thickness of about 0,1 .mu.m for 25 kV electrons.

Electron image projector

An electron beam apparatus comprising a semiconductor electron emitter whose emissive surface dimensions are determined by dimensions of a p-n junction provided in the semiconductor element. By optimizing the dimensions of the emissive surface in relation to the electron-optical properties of the apparatus, an emitter is realized which combines optimum beam formation or imaging with a sufficiently large beam current and a high beam current density as required by the apparatus.

Electron beam apparatus comprising a semiconductor electron emitter

In a beam shaper superpositions of a deformed first diaphragm and a deformed or non-deformed second diaphragm can be realized by means of a quadrupole system. As a result of this a great freedom for adapting the spot cross-section to the patterns to be formed is obtained, as a result of which the number of writing pulses per pattern and hence the writing time for, for example, a chip can be considerably reduced and in particular non-orthogonal and non-linear transistions in the patterns can be written with greater definition.

Charged particles exposure apparatus having an optically deformable beam

By using, in beam path correction, a three-point adjustment of the beam wobbler, the beam path can be optimized for realizing minimum picture errors in the apparatus. For different lens energizations a picture-shifting correction can simply be carried out dynamically.

Method of beam centering

An apparatus for energy-selective visualization of a beam of charged particles emerging from an object is equipped with a double-focusing energy analyzer which is provided with a two-dimensional entrance diaphragm. For visualization of both an image and a spectrum, an optical imaging system behind the analyzer is preferably equipped with one or more quadrapole lenses. An illumination system for an object to be examined is preferably equipped with a system for a sequential partial illumination of the object.

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Eindhoven, Netherlands

Karel D Van Der Mast